Thanks again, John.
--- In [email protected], John Mahony
<[EMAIL PROTECTED]> wrote:
>
> ----- Original Message ----
> > From: hewholooks <[EMAIL PROTECTED]>
> >
> > Thanks John.
> >
> > Looks like I somehow inadvertently deleted my original message -
glad
> > you left it quoted here.
> >
> > Followup question:
> >
> > On the AP GTO mount yahoo group, it was explained to me that the
AP
> > mounts have two different align to the stars functions; Sync and
> > ReCalibrate. Recalibrate is the function of choice as it ignores
> > whether the counterweight shaft is down or not and simply
realigns
> > with the star grid, where sync assumes the shaft is down, and if
it's
> > not (like if you are just past meridian, but now lets say the
scope
> > is west of meridian, but still tracking a star in the west) then
the
> > mount could get into some dangerous contortions later in slewing.
> >
> > Does CDC sync button cause a sync or a realign in AP mounts?
>
> Unfortunately I know almost nothing about AP's goto system. And it
might depend on how you connect. I assume there's an ASCOM driver
for AP's system, but I've heard AP also has an "LX200 simulator"
mode, left over from pre-ascom days, so it can work with generally
any software that can control an LX200 . So there are two ways to
connect.
>
> > If I hit the realign or sync function on the AP handcontroller,
will
> > the pointer in CDC move to (sync with) the target automatically
(like
> > they do when you align from the EQMOD control in the EQ mounts)?
>
> I think so. CdC just periodically (once per second, I think) asks
the scope's computer where it's aimed, so it can display the
pointer. So if you've got CdC set to show or track the scope
position, it would update when the scope's computer does.
>
> -John
>
>
>
> >
> > --- In [email protected], John Mahony
> > wrote:
> > >
> > > For most scope use, CdC (and most any general charting program)
> > isn't really involved in the alignment procedure- once you align
the
> > scope using the scope's built-in computer and keypad, CdC merely
asks
> > the scope's computer where it's aimed so it can display the
position,
> > and it can send goto commands to the scope. It doesn't get
involved
> > in how the alignment is done, so pointing accuracy will depend
only
> > on the AP mount and its own computer.
> > >
> > > But I remember seeing something in the documentation about using
> > > CdC with systems where you have 2 encoders and a black box that
> > sends
> > > those signals to a computer, but the scope doesn't have its own
> > > built-in computer (something like JMI's "Software Guided
Telescope"
> > systems). In
> > > that case, CdC does the alignment. This is an old feature for
basic
> > > systems, so I thought it would use just a basic 2-star
> > > alignment, not the type of multi-star alignment needed to
compensate
> > > for orthogonality errors. However I just looked again:
> > >
> > > and it looks moderately advanced- there are settings for mount
> > angle errors. But it's still an early feature based on an old
S&T
> > article from the very early days of computerized amateur scopes,
so
> > it looks like it doesn't calculate the mount angle errors from
star
> > positions- you have to figure them out on your own (Z1 is RA/dec
axis
> > perpendicularity error, which should be insignificant on an AP
> > mount. Z2 appears to be optical/dec axis perpendicularity error,
> > commonly called "cone error" by GEM owners, and this is where you
get
> > errors mounting different scopes on a GEM without shimming.) You
can
> > find cone error in an equatorial mount by aiming nominally to 90
dec
> > and looking through the EP while rotating the scope in RA.
Ideally,
> > at 90 dec the OTA is parallel to the mount's RA axis, so the
image
> > should rotate around the center of the FOV. If not, tweak the
dec to
> > minimize the error, (this removes any error in the 90 dec
setting),
> > and what's left is
> > > cone error.
> > > And I have no idea whether this whole method of connecting to
CdC
> > will be compatible with the AP system.
> > >
> > > Syncing on a nearby star is generally pretty accurate, and easy
to
> > do with CdC since you can just click on any star and have the
scope
> > move there, and then center, and sync via CdC. For long slews,
if
> > orthogonality errors make your pointing bad, you can go across
the
> > sky in multiple smaller jumps, syncing along the way.
> > >
> > > -John
> > >
> > >
> > >
> > >
> > > ----- Original Message ----
> > > > From: hewholooks
> > > >
> > > > Patrick or anyone else in the know,
> > > >
> > > > How does CDC perform with the AP mounts - specifically the AP
> > 900GTO?
> > > >
> > > > The goto function on the AP mounts reputedly is very
dependent on
> > > > orthogonality of mount with scope and the system AP uses has
no
> > plate
> > > > solving capabilities. Since I like to image with different
scopes
> > on
> > > > my current mount (EQ-6 with EQMOD using CDC), this troubles
me
> > since each
> > > > scope will most likely be pointed differently when attached
to
> > the
> > > > mount for the evening. With EQMOD, I can plate solve each
time I
> > set
> > > > up with a different scope and have accurate gotos - maybe not
> > with CDC
> > > > and the AP system.
> > > >
> > > > I am not a big user of the goto system, but usually will sync
on a
> > > > star near the object I want to image and the goto is only a
few
> > degrees in
> > > > distance. With EQMOD, the goto is more than adequate for
that
> > > > distance, but using CDC with the AP mount....?
> > > >
> > > > Any practical experience or advice considering the above
> > circumstances?
> > > >
> > > > Hunter
> > > >
> > > >
> > > >
> > > >
> > > > Yahoo! Groups Links
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > >
> > >
> >
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> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
>
>
>
>
>
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